Eye tracking is the process of measuring either the point of gaze (i.e. where one is looking) or the motion of an eye relative to the head. Typically, an eye tracker is a device used for measuring eye movements and/or positions. There are a number of methods for measuring eye movement. Currently, the most widely used are video-based eye trackers, by which a camera focuses on one or both eyes and records their movement as the viewer looks at some kind of stimulus. Most modern eye-trackers use the center of the pupil and infra red non-collimated light to create corneal reflections. The vector between the pupil center and the corneal reflections may be used to compute the point of regard on surface or the gaze direction.
Eye tracking setups vary greatly; some are head-mounted, some require the head to be stable (for example, with a chin rest), and some function remotely and automatically track the head during motion.
The eye tracking technology is used in various fields. For example for detecting a gaze of a driver of a vehicle in order to assist the driver's driving (e.g. for determining whether or not the driver is driving inattentively).
Another known technique is detecting movement of a pupil of a wearer of a head-mounted device, and determining, based on the detected movement, inputs to a user interface. For example, by using eye gaze detection, the device may change a tracking rate of a displayed virtual image based on where the user is looking. Gazing at the center of the field of view may allow for fine movements of the virtual display. Gazing near an edge of the field of view, may provide coarser movements.
When reading a text on the screen, the reader might sometimes reach a word or a phrase which is unrecognized to him, or is difficult for him to understand within the current context. Such a person can either skip the unrecognized word/phrase or otherwise would need some assistance in order to understand the word/phrase before continue reading. In the latter case, the prior art solutions require that the reader would select the word/phrase and manually search for help or information at the Web or on his own electronic device (e.g. a computer, a tablet, a smart phone, etc.). There are some applications that allow the user to mark or select the unrecognized word/phrase and then provide the result of an Internet search on top of one's current screen, all without having to switch to another application.
Still, even such a solution slows down the reading, and many times causes loss of focus and consequently the reader might fail to complete the reading.